Contact sports, such as American football, hockey, baseball, and lacrosse, require the use of protective helmets to decrease the likelihood of head injury while playing the sport. Modern helmets are generally comprised of four features: a plastic outer shell, a liner typically comprising a shock absorbing material and air, a metal facemask, and a chin strap.
The National Operating Committee on Standards for Athletic Equipment (NOCSAE) has established standards for testing football helmets. Early test standards were directed at measuring linear accelerations in a head form while outfitted with a helmet. During testing, the helmeted head form is struck with an impact force at different head orientations. More particularly, the helmeted head form is suspended above a metal and rubber block before being released to cause it to strike the block after free falling from a noted height. More recent test standards have been developed that measure both linear and rotational acceleration forces in a head form. In one such test, a striking force is imparted to a helmeted head form mounted on an adjustable platform via weighted pendulum.
These standards and methods only represent the player's head. Therefore, the helmets are not tested using the full mass and dynamics of the human body behind it. In addition, the effects of the presence of other safety equipment, such as shoulder pads, are not considered. Furthermore, the tests do not measure forces and moments in the neck that are caused by impact forces when the helmeted head is struck.
From the above discussion, it can be appreciated that it would be desirable to have a system and method for testing protective helmets that more accurately reflects the impacts experienced in the real world when playing a sport.